Treating hydrocarbon fluids



lg 24', w48. c. E. HEMMINGER ETAL 2,447,577

TREATING HYDROCARBON FLUIDS Filed March 25, 1943 Omv Patented' Aug. 24, 1948 TREATING HYDROCARBON FLUIDS Charles E. Hemminger, Westfield, and Charles W. Tyson, Summit, N. J., assignors to Standard Oil Development Company, a corporation of Dela- Ware Application March 25, 1943, Serial No. 480,448

Claims. (Cl. 196-52) This invention relates to catalytic conversion of hydrocarbons and more particularly relates to catalytic conversion of residual stocks separate from lighter fractions from the same hydrocarbon feed stock.

According to our invention a crude oil, topped crude or a relatively h'eavy oil containing unvaporizable constituents is separated into a gas oil fraction which can be substantially completely vaporized and a residual hydrocarbon fraction containing vaporizable and unvaporizable constituents. The two hydrocarbon fractions are separately converted in different zones in the presence of a powdered catalyst as the optimum conditions are not the same for bothiractions and this forms one of the advantages of our process. When residual oil is mixed with powdered catalyst, inorganic salts or material is deposited on the catalyst particles and the activity of the catalyst is reduced. By separate treatment of the two fractions a part of the catalyst from the heavy hydrocarbon cracking may be removed as desired and replaced-by catalyst from the gas oil cracking and the activity of the catalyst maintained higher for both fractions by using fresh catalyst in the gas oil cracking step.

The gas oil fraction or lighter fraction is mixed with hot regenerated powdered catalyst and the mixtureis passed to a reaction zone Where proper temperatures and contact times are maintained to obtain the desired conversion. The reaction products in vapor form are separated from spent powdered catalyst and at least part of the spent catalyst may be mixed with the residual fraction or reduced crude oil for converting the residual fraction or reduced crude.

The residual oil is mixed with regenerated catalyst from the lighter oil cracking step and the mixture is passed through a heating zone to vaporize and convert the heavy or residual oil so that the unvaporized portions of the oil are absorbed on the catalyst and converted to lower boiling constituents. In this way the products of t'aie conversion of the residual oil are only vapors and coke and the mixture leaving the heating zone comprises vapors and spent powdered catalyst. The reduced crude oil during the conversion deposits inorganic material o n the catalyst and on regenerating the catalyst some of the inorganic material is decomposed to compounds which reduce the activity of the catalyst.

The heavy or residual oil is Preferably passed through a separate reaction zone, or the conlversion may be effected in the heating zone and the mixture of the reaction products and catalyst passed to a separating means to remove a large part of the vaporous reaction products from the powdered catalyst. A part or all of the spent powdered catalyst used for catalytic conversion of the heavy or residual oil is separately regenerated and returned for reuse in the catalytic conversion of the heavy or residual oil; or a part thereof may be regenerated in the same regeneration zone used for regenerating catalyst from the gas oil conversion zone.

The powdered catalyst used for the residual stock deteriorates faster because of the deposition of inorganic salts or material on the catalyst 'during vaporization and conversion of the residual version of the heavy or residual oil is taken from thegas oil or lighter oil conversion zone after it has been used in the conversion of the lighter oil stock. In this way more active catalyst is maintained in both zones.

More specifically, petroleum crude oil is dis-V A character I0 designates a line for introducing 4crude petroleum oil or topped crude oil into a crude still l`2. The crude still is heated in any suitable manner to vaporize a large portion of the crude oil. Virgin gasoline is taken overhead through line I4. A heavy naphtha fraction may be removed from the upper portion of the crude still through line I6. A relatively light gas oil -fraction is removed from the still l2 through line I8 and may be passed through a heating 0011.22 in heating zone 24 to vaporize the relatively light oil `before it is mixed with hot regenerated catalyst. In cases where the hot regenerated catalyst is at a suiiiciently high temperature and in a large amount, the gasf oil fraction may be passed around heating zone 24 through line 26 as a liquid and mixed with the hot regenerated catalyst .from standpipe 2a to vaporize the gas oil and to raise it to conversion temperature. Standpipe 28 is provided with a control valve 82 such as a slide valve for controlling the amount of catalyst introduced into line 34 for admixture with the gas oil.

The mixture of catalyst and oilvapors is then passed through line 36 into the bottom portion of a reaction zone 38 provided with a bottom distribution plate or grid member 42 arranged in the bottom portion of the reaction zone. The grid member functions to distribute evenly the powdered catalyst in the oil vapors across the cross-sectional area of 'the reaction zone. It is noted that the diameter of the reaction zone is much greater than the diameter of the inlet pipe 38 and due to this larger diameter there is a decrease in the velocity of the vapors passing upwardly through the reaction zone 38. The velocity of the vapors passing through thereaction zonel is so selected that the mixture of powdered catalyst and oil vapors in the reaction zone 38 assume many of the characteristics of a liquid and form a iluidized mixture having a level 44 similar to a liquid.

The reaction products in vapor form and powdered catalyst pass overhead through line 46 to a separating means 48 for separating dry powdered catalyst from reaction vapors. The reaction vapors pass overhead through line 50. The separating means is shown as a cyclone separator in the drawing but other separating means may be used. While only one cyclone separator has been shown on the drawing, it is to be understood that two or three cyclone separators may be used in series to eiect substantially complete separation of powdered catalyst from the reaction products in vapor form. The separated powdered catalyst is received in the bottom portion 52 of the cyclone separator and passed to a standpipe 54. The spent catalystin standpipe 54 is regenerated as will be presently described. A portion of the spent catalyst may be used for converting residual stock as will be hereinafter described in greater detail. Standpipe 54 is provided with a manifold 56 and branch lines 58 for introducing aerating gas into the powdered catalyst in the standpipe to maintain it in iluidized condition.

All or a portion of the spent catalyst is passed through a short standpipe 82 which branches oi the lower portion of standpipe 54 and which ls provided with a control valve 84 near its lower portion vfor controlling the amount of catalyst being introduced into line 66.` Regenerating gas such as air, other oxygen-containing gas or other gas is introduced into line 66 through line 68 and the mixture is passed upwardly into the lower portion of a regeneration zone 12 provided with a, bottom distribution plate or grid member 1|. The grid member acts to distribute evenly the powdered material and -gases across the area of the regeneration zone. The regeneration zone has a much larger diameter than the inlet pipe 66 and because of this increase in diameter there is a decrease in the velocity of the gases passing through the regeneration zone.

Ihe velocity of the gases passingthrough the regeneration zone is so selected that the powdered catalystassumes the appearance of a liquid having a level 16. 'I'he powdered catalyst is in -a turbulent condition and good mixing is eected so that the temperature during regeneration is substantially uniform throughout the fluidized mixture in the regeneration zone.

Regenerated powdered catalyst and regeneration gases pass overhead through line I8 to a separating means 82 which is shown as a cyclone separatorA in the drawing. Other separating means may be used. More than one cyclone separator may be used. If desired, a Cottrell precipltator may be used as a final separating means to separate substantially all of the powdered catalyst from the regeneration gases.

The regeneration gases pass overhead through line 84 to the atmosphere and the separated regenerated catalyst is collected in hopper 86 of the separating means 82 from which it is passed to a standpipe 28. 'I'he standplpe 28 is provided with a manifold 92 and branch lines 94 for introducing aerating gas into the standpipe to maintain the regenerated catalyst in fiuidized condition so that a hydrostatic pressure is developed at the bottom of the standpipe. The regenerated catalyst is fed into the line 34 as above del scribed.

Returning now to the crude still I2. the reduced crude oil or bottoms are removed from the bottom through line v96 and passed into the lower portion of a. fractionating tower 98. The reaction `product vapors from the separating means 48 are passed through line 58 into the bottom portion of the fractionating tower 88. These vapors are at a relatively high temperature and as they are introduced into the tower 88 below the point of introduction of the bottoms through line 96, the bottoms are further vaporized and heat is supplied for fractionating the vapors. A catalytically cracked gasoline is taken overhead from the fractlonating tower 98 through line |02. A heating oil may be removed as a. relatively light fraction through line |84. A gas oil fraction is removed through line |86 and a portion of this fraction may be removed from the system through line |08. All or a portion of the gas oil fraction may be passed through line H2 and introduced into line 34 where it is mixed with gas oil coming from the crude still |2 before the other oil is mixed with the regenerated catalyst.

Reduced crude oil along with any unrecovered catalyst coming to fractionator 88 through line 58 is withdrawn from the bottom of the fractionating .tower 98 through line H4. The reduced crude is mixed with regenerated catalyst from standpipe I|6 which contains regenerated catalyst from the crude oil cracking step presently to be described. Standpipe H8 is provided with a control valve H8 at its lower end to control the amount of catalyst being mixed with the reduced crude oil or bottoms passing through line H4.

The mixture of residual oil and powdered catalyst is preferably passed through a heating coil |22 in heating zone |24 to vaporize at least a portion of `the oil and to convert the unvaporizable constituents to coke and lighter constituents so that a dry mixture results. The dry mix' ture of partly converted products and powdered catalyst is then passed through line |26 and is preferably introduced into a separate reaction zone |28 provided with a grid member |32 wherein the catalyst is in a dry fluidized mixture hav'- ing a level |33. Reaction zone |28 is similar to reaction zone 38 above described and the hydrocarbons are further catalytically converted to form motor fuel constituents. Instead of passing through the separate reaction zone |28, the heating coil |22 may serve as the reaction zone and the vaporous reaction products and powdered catalyst as a dry mixture may be passed through line |34 to a separating means |35.

naar? 1 thedry reaction product vapors `and dry powdered catalyst pass `overhead through line |88 to the separating means |88 above referred to.

Where the reduced crude oil in line I 4Il is-at a suillciently high temperature and a sumcient amount of hot catalyst is 'used.'the heating zone |24 may be omitted kand vthe reduced crude oil and powdered catalyst passed through line |4| around the heatingzone |28 and intoline |84 to separating means |85 wherein drycatalyst powbe used and asa last separation means a Cot.- trell precipitator may be used. Ihe regeneration gases leave through line |81k and may be vented to the atmosphere. a

The separated regenerated catalyst accumulates in the bottom |88 of separation means |88 and is introduced Vinto standpipe H8 in which the drawing but other separating mea-ns may be used and more than one cyclone separator may be used. The vapors containing entrained catalyst pass overhead through line |82 and may be passed through separating means I8 but are prei'- erably passed through by-pass line i which connects with line 50.

The separated catalyst is collected in the bo tom |48 of the separating means |38 and introduced into a standpipe |18 provided with manithe reaction zone 88. By using a separate catal lyst for the residual oil conversion. a portion oi' the deactivated catalyst can be removed from the system through valve'd line |88 leading from standpipe |88. v

`The removed catalyst is replaced by catalyst from the system ln which gas oil or the lighter hydrocarbon is converted. For example. regenerated catalyst from standpipe 28 is passed to branch standpipe |62 having a topcontrol valve |08 and a bottom control valve |85. The desired amount of make-up catalyst for the reduced crude conversion is introduced into line iid from standpipe |82. ostandpipe |82 has aerating lines |88 and a manifold |12 for feeding suitable aerating gas thereto to maintain the catalyst in dry iiuidized condition. By removing spent catalyst from the residual conversion step and replacing it with regenerated catalyst from the gas oil or lighter hydrocarbon conversion step, the activity of the catalyst in both systems is mainf tained at a higher level.

Fresh make-up catalyst is supplied to the regeneration zone 12 through line |18 as desired and this fresh catalyst is used in the conversion zone 3u wherein the gas oil or lighter hydrocarbon stock is converted. In this way the fresh catalyst is first used where it isleast deactivated and is then transferred to the residual oil conversion step where greater deactivation occurs.

The regeneration of the spent catalyst-from standpipe |68 will now be described.. The catalyst is mixed with' a regenerating gas such as air introduced through line |15 and the. mixture passed through line |16 and into the bottom of a second regeneration zone |18 having a bottom liar to regeneration zone 12 and the powdered Other separation means may the regenerated catalyst is maintained in dry iluidized condition by aerating lines |82 fed from manifold i to produce a hydrostatic pressure at the bottom of the standpipe Ill. This regenerated catalyst is used for the reduced crude oil reconversion.

Instead oi' using only regenerated catalyst from standpipe ||8 for the reduced crude oil conversion and make-up regenerated catalyst from standpipe |82 for the reduced' crude oil conversion. a portion of the spent catalyst from the gas oil or relatively light hydrocarbon stock conversion step maybe used. Spent catalyst from this last mentioned step is passed into standpipe 288 having top control valve 202 and bottom control valve 288. standpipe 200 feeds into line III conveying reducedcrude oil and bottoms containing recycle stock from fractionator 88. Aeratlng lines 286 and manifold 208 are provided ior aerating lthe spent catalyst in standpipe 200.

The catalyst from hopper bottom |88 may-also be introduced into line |28 after furnace |88 through standpipe 208, a division oi standpipe and regulated by valve 2id.

In cases where the crude oil has' a very high' salt content it may be desalteo'i before being used in this process. i

A specific example of catalytic conversion oi' hydrocarbonoil will now be given but it is to be understood that the example is by way of illustration only and the invention is not to be limited to the specic example. A crude oil such as an East Texas crude having an A. P. I. gravity of about 37.5 is introduced into the crude still and virgin heavy naphtha through line l0. A gas oil boilingbetween about 450 F. and 850 F., is

removed through line |8. The temperature oi' this gas oil is about F. The catalyst may be any suitable cracking catalyst such as acid treated bentonite clays, synthetic silica alumina gels or silica magnesia gels, etc. of a size between about 200 and 400 standard mesh and liner. to produce high octane gasoline the catalyst to oil ratio by weight is about 3 to 25 with 5 to 15 preferred. y

Where the regenerated catalyst in standpipe 28 is at a temperature of about 1100'l F. and where a relatively large ratio of catalyst to oil is used, there is suillcient heat supplied by the catalyst to vaporize the gas oil and raise it to a temperature of about 875 Il'. to 900 F. in the reaction zone 38 to bring about the desired conversion. The

separated reaction product vaporsr passing.

through line 50 are at a temperature of about 900 F.

The `bottoms from crude still yI2 are at a temperature of about 725 F. and these bottoms are mixed in fractionator 88 with the reaction product vapors from line 50 to ash off any volatile constituents from the reduced crude oil. The residual oil passing from the bottom o! fractionating tower through line ||4 is at a temperature of about 800 F. The residual oil is mixed with regenerated powdered catalyst from standpipe ||8. More than about three parts ot catalyst by weight to one part' of oil by weight is used The catalyst is For the cracking of the gas oil` maintained in reaction zone III at this temperature in the presence oi the catalyst for about 0.5 minute to eilectthe conversion oi the residual oil to gasoline, gas oil and coke which is deposited on the catalyst.

oil is cracked at a higher temperature than the temperature used for cracking the gas oil in reaction zone 38. Also, preferably larger. amounts of catalyst per unit of oil are used in cracking the reduced crude bottoms than is used in cracking the gas oil inthe reaction zene 38. By separately cracking these dinerent fractions, the yield of motor i'uel or gasoline is increased and better gasoline is produced. y'in addition, the process may be so carried out that catalyst whlchis deactivated by reduced crude oil may be removed from the system and replaced by spent catalyst from the gas oil cracking step in the process, fresh make-up catalyst being added to the gas oil cracking step. v

Furthermore, this invention contemplates the use of a residual stock containing non-vaporizable constituents as a feedstock for a catalytic cracking operation. In this operation a suiicient amount of powdered catalyst is used to adsorb the liquid and sumcient heat is supplied either by the powdered Ycatalyst or by heating means to vaporize and convert the residual oil to vapors and coke or carbonaceous material so that the mixture of residual oil and catalyst after mixing and heating forms a dry mixture which can be passed through pipes or vessels as a suspension.

When spent catalyst is removed from the reduced crude oil conversion step through line i58, make-up catalyst is supplied from the gas oil conversion step through standpipe |62. Fresh catalyst is then added to the gas oil conversion step through line |14. The catalyst in the gas oil conversion step has a higher activity because the catalyst is added to and removed from the system at a higher rate than would be normally accomplished in the gas oi1 conversion step. The activity of the catalyst in the reduced crude oil conversionstep will he greater for the same reason and also for the reason that the amount of inorganic material deposited from the reduced crude or other heavy oil will be less per unitof catalyst than if the reduced crude oil conversion step were fed with fresh catalyst above.

Instead of using the type of vessel or zone shown in the drawing where the reaction products or gases and' powdered catalyst pass overhead, lwe may use reaction zones or vessels including regeneration zones or vessels where the vapors or gases pass overhead with a small amount of entrained catalyst but the bulk of the catalyst' is taken of! from the. bottom of the reaction zones and introduced into a standpipe associated with the respective zones from which it is circulated to another part of the process.

'This invention is not restricted to the processing of the separate cuts oi a given crude but may be used. to process any two oils, one a gas oil or the like and the other a residual or contaminated oil (containing materials affecting catalyst activity) from any source.

While we have shown one form o! apparatus and have given one specific example of a hydro carbon conversion process, it is to be understood v 10. From the above, it will be seen that the .residual 8 that these areby way of illustrationonly and modiiications and changes may be made without departing from-the spirit of our invention.

We claim:

1. AV process for treating hydrocarbon iluids which comprises separating a hydrocarbon oil into a residual oil fraction containing vaporizable and unvaporizable constituents Aand a condensate traction, contacting the condensate fraction with hot catalyst particles to vaporize the condensate fraction and raise it to conversion temperature, passing the mixture'into a reaction zone,

separating vaporous reaction products from dry spent catalyst, mixing the residual oil fraction with hot regenerated catalyst, heating the residual oil traction and catalyst to a higher temperature than said tlrst mentioned temperature to convert and substantially completely vaporize the residual oil fraction leaving unvaporized deposits on the catalyst, separating vaporous reaction products from dry spent catalyst. regenerating at least a portion of the first mentioned spent catalyst and using most of the regenerated hot catalyst for admixture with the condensate. fraction and at least a part as the catalyst for the residual oil fraction conversion.

2. A process according to claim 1 'wherein at least part of the ilrst mentioned spent catalyst is mixed withl the residual oil fraction. W

3. A process according to claim l -wherein the first mentioned spent catalyst is regenerated and thek regenerated catalyst is used as make-up catalyst for the residual oil fraction conversion, at least part of the second mentioned spent catalyst is removed from the system and fresh make-up catalyst is used for the condensate fraction conversion step.

4. A process for treating hydrocarbon fluids which comprises separating a hydrocarbon oil into a residual fraction containing inorganic material and a gas oil, heating the gas oil, mixing the heated gas oil with catalyst particles in a reaction zone, separating vaporous reaction products from spent catalyst. regenerating-th spent catalyst, mixing the residual traction with at least a part ot the regenerated catalyst to form a dry mixture, heating the residual fraction and catalyst to substantially completely vaporize the residual oil by converting heavy ends to vapors and coke, separating vaporous reaction products from :lry coked catalyst. regenerating the last mentioned catalyst .and using at least part or it for adnuxture with.

which comprises separating a hydrocarbon oil into a condensate oil and a residual fraction, mixing the condensate oil with hot regenerated powdered catalyst to vaporize the oil and raise it to conversion temperature, passing the mixture into a reaction zone, removing reaction products and spent catalyst from said reaction zone, regenerating the withdrawn'spent catalyst, mixing the residual fraction withat least a part of the regenerated catalyst, heating the residual oil and catalyst tc convert the residual fraction to vapors and unvaporizedresidues deposited on the catalyst and to orm a dry mixture, separating dry reaction products from the lastmentioned `dry catalyst, regenerating at least a portion of the last mentioned catalyst and using the regenerated hot catalyst for admixture with the residual fraction.

6. A process according to claim 5 wherein the temperature for convertingthe condensate oil is lower than the temperature of conversion of the residual fraction.

7. A process according to claim wherein the catalyst to oil ratio is higher for the conversion of the residual fraction than for the conversion of the condensate oil.

8. A process for treating hydrocarbon uids which comprises separating a hydrocarbon oil into a residual fraction containing inorganic material and a condensate oil, mixing the condensate oil with powdered catalyst and heating the oil to conversion temperature, passing the mixture into a reaction zone, separating vaporous reaction products from spent catalyst, regenerating the catalyst, passing the residual fraction to a fractionating zone, contacting the residual fraction with hot vaporous reaction products to heat the residual fraction and cool the .reaction products, removing bottoms from said fractionating zone, mixing the bottoms with at least a part of the regenerated catalyst, heating the bottoms and catalyst to convert the bottoms to vapors and deposit inorganic and organic material on the catalyst, separating vaporous reaction products from the last mentioned dry spent catalyst, regenerating at least a portion of the last mentioned catalyst and using the regenerated catalyst for admixture with the bottoms.

9. A process for treating hydrocarbon iluids which comprises separating a hydrocarbon oil into a condensate oil and a residual fraction, mixing the condensate oil with hot regenerated powdered catalyst to vaporize the oil and raise it to conversion temperature, passing the mixture into a reaction zone, separating reaction products from spent catalyst, regenerating at least a portion of the spent catalyst in a regeneration zone, mixing the residual fraction with at least a portion of the regenerated catalyst, heating the residual fraction and catalyst to convert the residual fraction to vapors and coke and'to form a dry mixture, separating reaction products from the last mentioned catalyst, regenerating the last mentioned catalyst in another regeneration zone, using the last mentioned regenerated catalyst at least in part for admixture with the residual fraction and removing another part of the last mentioned regenerated catalyst from the system.

10. A process according to claim 9 wherein make-up catalyst for the condensate oil conversion is fresh catalyst and make-up catalyst for the residual fraction is part of the rst mentioned regenerated catalyst.

11. A process for treating hydrocarbon fluids which comprises separating 'a hydrocarbon oil into a condensate oii and a residual fraction, mixing the condensate oil with hot regenerated powdered catalyst to vaporize the oil and raise catalyst and using the last mentioned regenerated hot catalyst for admixture with the residnain-action.

12. A process according to claim 11 wherein fresh make-up catalyst is added to the condensate oil conversion step.

13. A process for treating hydrocarbon fluids which comprises separating a hydrocarbon oil into a residual oil fraction containing vaporizable and unvaporizable constituents and a condensate fraction, contacting the condensate fraction with catalyst particles in a reaction zone maintained under reaction conditions, separating vaporous reaction products from dry spent catalyst, contacting the residual oil fraction with solid particles in a second reaction zone maintained under such conditions to convert the residual oil fraction to vapors and unvaporized deposits which collect on the solid particles, separating vaporous reaction products from substantially dry solid particles, regenerating at least a portion of the spent catalyst and recycling most of the regenerated catalyst to said rst reaction zone and at least a part of the regenerated catalyst to said second reaction zone.

14. A process for treating hydrocarbon iluids which comprises mixing a gas oil with catalyst particles in a reaction zone maintained under conversion conditions wherein gas oil vapors are converted to gasoline, separating vaporous reaction products from dry spent catalyst, regenerating the spent catalyst, recycling at least part of the regenerated catalyst to said reaction zone, mixing a liquid residual oil containing vaporizable and unvaporizable constituents with catalyst particles in a second reaction zone maintained under conversion conditions to convert the residual oil to vapors and coke which is deposited on the catalyst particles, separating the last mentioned vaporous reaction products from dry coked catalyst, regenerating the last mentioned catalyst, recycling at least part of the last mentioned regenerated catalyst to said second reaction zone and using at least part of the rst mentioned regenerated catalyst as make-up catalyst for the residual oil conversion step and adding fresh active catalyst to said i'lrst reaction zone as make-up catalystI so that the most active catalyst is in said first reaction zone and less active catalyst is in said second reaction zone. 415. A method according to claim 14 wherein the conversion temperature in said second reaction zone is higher than in said first reaction zone.

CHARLES E. HEMMINGER.

CHARLES W. TYSON.

REFERENCES CITED The following references are of record in the file of this patent:

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